/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2007 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *	notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *	notice, this list of conditions and the following disclaimer in the
 *	documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *	contributors may be used to endorse or promote products derived from
 *	this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.objectweb.asm.tree;

import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.Attribute;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Label;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;

import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;

/**
 * A node that represents a method.
 * 
 * @author Eric Bruneton
 */
public class MethodNode extends MemberNode implements MethodVisitor {

	/**
	 * The method's access flags (see {@link Opcodes}). This field also
	 * indicates if the method is synthetic and/or deprecated.
	 */
	public int access;
	/**
	 * The method's name.
	 */
	public String name;
	/**
	 * The method's descriptor (see {@link Type}).
	 */
	public String desc;
	/**
	 * The method's signature. May be <tt>null</tt>.
	 */
	public String signature;
	/**
	 * The internal names of the method's exception classes (see
	 * {@link Type#getInternalName() getInternalName}). This list is a list of
	 * {@link String} objects.
	 */
	public List<String> exceptions;
	/**
	 * The default value of this annotation interface method. This field must be
	 * a {@link Byte}, {@link Boolean}, {@link Character}, {@link Short},
	 * {@link Integer}, {@link Long}, {@link Float}, {@link Double},
	 * {@link String} or {@link Type}, or an two elements String array (for
	 * enumeration values), a {@link AnnotationNode}, or a {@link List} of
	 * values of one of the preceding types. May be <tt>null</tt>.
	 */
	public Object annotationDefault;
	/**
	 * The runtime visible parameter annotations of this method. These lists are
	 * lists of {@link AnnotationNode} objects. May be <tt>null</tt>.
	 * 
	 * @associates org.objectweb.asm.tree.AnnotationNode
	 * @label invisible parameters
	 */
	public List<Object>[] visibleParameterAnnotations;
	/**
	 * The runtime invisible parameter annotations of this method. These lists
	 * are lists of {@link AnnotationNode} objects. May be <tt>null</tt>.
	 * 
	 * @associates org.objectweb.asm.tree.AnnotationNode
	 * @label visible parameters
	 */
	public List<Object>[] invisibleParameterAnnotations;
	/**
	 * The instructions of this method. This list is a list of
	 * {@link AbstractInsnNode} objects.
	 * 
	 * @associates org.objectweb.asm.tree.AbstractInsnNode
	 * @label instructions
	 */
	public InsnList instructions;
	/**
	 * The try catch blocks of this method. This list is a list of
	 * {@link TryCatchBlockNode} objects.
	 * 
	 * @associates org.objectweb.asm.tree.TryCatchBlockNode
	 */
	public List<TryCatchBlockNode> tryCatchBlocks;
	/**
	 * The maximum stack size of this method.
	 */
	public int maxStack;
	/**
	 * The maximum number of local variables of this method.
	 */
	public int maxLocals;
	/**
	 * The local variables of this method. This list is a list of
	 * {@link LocalVariableNode} objects. May be <tt>null</tt>
	 * 
	 * @associates org.objectweb.asm.tree.LocalVariableNode
	 */
	public List<LocalVariableNode> localVariables;

	/**
	 * Constructs an unitialized {@link MethodNode}.
	 */
	public MethodNode() {
		this.instructions = new InsnList();
	}

	/**
	 * Constructs a new {@link MethodNode}.
	 * 
	 * @param access the method's access flags (see {@link Opcodes}). This
	 *		parameter also indicates if the method is synthetic and/or
	 *		deprecated.
	 * @param name the method's name.
	 * @param desc the method's descriptor (see {@link Type}).
	 * @param signature the method's signature. May be <tt>null</tt>.
	 * @param exceptions the internal names of the method's exception classes
	 *		(see {@link Type#getInternalName() getInternalName}). May be
	 *		<tt>null</tt>.
	 */
	public MethodNode(
			final int access,
			final String name,
			final String desc,
			final String signature,
			final String[] exceptions) {
		this();
		this.access = access;
		this.name = name;
		this.desc = desc;
		this.signature = signature;
		this.exceptions = new ArrayList<String>(exceptions == null
				? 0
				: exceptions.length);
		boolean isAbstract = (access & Opcodes.ACC_ABSTRACT) != 0;
		if (!isAbstract) {
			this.localVariables = new ArrayList<LocalVariableNode>(5);
		}
		this.tryCatchBlocks = new ArrayList<TryCatchBlockNode>();
		if (exceptions != null) {
			this.exceptions.addAll(Arrays.asList(exceptions));
		}
	}

	// ------------------------------------------------------------------------
	// Implementation of the MethodVisitor interface
	// ------------------------------------------------------------------------
	public AnnotationVisitor visitAnnotationDefault() {
		return new AnnotationNode(new ArrayList<Object>(0) {

			public boolean add(final Object o) {
				annotationDefault = o;
				return super.add(o);
			}
		});
	}

	@SuppressWarnings("unchecked")
	public AnnotationVisitor visitParameterAnnotation(
			final int parameter,
			final String desc,
			final boolean visible) {
		AnnotationNode an = new AnnotationNode(desc);
		if (visible) {
			if (visibleParameterAnnotations == null) {
				int params = Type.getArgumentTypes(this.desc).length;
				visibleParameterAnnotations = new List[params];
			}
			if (visibleParameterAnnotations[parameter] == null) {
				visibleParameterAnnotations[parameter] = new ArrayList<Object>(1);
			}
			visibleParameterAnnotations[parameter].add(an);
		} else {
			if (invisibleParameterAnnotations == null) {
				int params = Type.getArgumentTypes(this.desc).length;
				invisibleParameterAnnotations = new List[params];
			}
			if (invisibleParameterAnnotations[parameter] == null) {
				invisibleParameterAnnotations[parameter] = new ArrayList<Object>(1);
			}
			invisibleParameterAnnotations[parameter].add(an);
		}
		return an;
	}

	public void visitCode() {
	}

	public void visitFrame(
			final int type,
			final int nLocal,
			final Object[] local,
			final int nStack,
			final Object[] stack) {
		instructions.add(new FrameNode(type, nLocal, local == null
				? null
				: getLabelNodes(local), nStack, stack == null
				? null
				: getLabelNodes(stack)));
	}

	public void visitInsn(final int opcode) {
		instructions.add(new InsnNode(opcode));
	}

	public void visitIntInsn(final int opcode, final int operand) {
		instructions.add(new IntInsnNode(opcode, operand));
	}

	public void visitVarInsn(final int opcode, final int var) {
		instructions.add(new VarInsnNode(opcode, var));
	}

	public void visitTypeInsn(final int opcode, final String type) {
		instructions.add(new TypeInsnNode(opcode, type));
	}

	public void visitFieldInsn(
			final int opcode,
			final String owner,
			final String name,
			final String desc) {
		instructions.add(new FieldInsnNode(opcode, owner, name, desc));
	}

	public void visitMethodInsn(
			final int opcode,
			final String owner,
			final String name,
			final String desc) {
		instructions.add(new MethodInsnNode(opcode, owner, name, desc));
	}

	public void visitJumpInsn(final int opcode, final Label label) {
		instructions.add(new JumpInsnNode(opcode, getLabelNode(label)));
	}

	public void visitLabel(final Label label) {
		instructions.add(getLabelNode(label));
	}

	public void visitLdcInsn(final Object cst) {
		instructions.add(new LdcInsnNode(cst));
	}

	public void visitIincInsn(final int var, final int increment) {
		instructions.add(new IincInsnNode(var, increment));
	}

	public void visitTableSwitchInsn(
			final int min,
			final int max,
			final Label dflt,
			final Label[] labels) {
		instructions.add(new TableSwitchInsnNode(min,
				max,
				getLabelNode(dflt),
				getLabelNodes(labels)));
	}

	public void visitLookupSwitchInsn(
			final Label dflt,
			final int[] keys,
			final Label[] labels) {
		instructions.add(new LookupSwitchInsnNode(getLabelNode(dflt),
				keys,
				getLabelNodes(labels)));
	}

	public void visitMultiANewArrayInsn(final String desc, final int dims) {
		instructions.add(new MultiANewArrayInsnNode(desc, dims));
	}

	public void visitTryCatchBlock(
			final Label start,
			final Label end,
			final Label handler,
			final String type) {
		tryCatchBlocks.add(new TryCatchBlockNode(getLabelNode(start),
				getLabelNode(end),
				getLabelNode(handler),
				type));
	}

	public void visitLocalVariable(
			final String name,
			final String desc,
			final String signature,
			final Label start,
			final Label end,
			final int index) {
		localVariables.add(new LocalVariableNode(name,
				desc,
				signature,
				getLabelNode(start),
				getLabelNode(end),
				index));
	}

	public void visitLineNumber(final int line, final Label start) {
		instructions.add(new LineNumberNode(line, getLabelNode(start)));
	}

	public void visitMaxs(final int maxStack, final int maxLocals) {
		this.maxStack = maxStack;
		this.maxLocals = maxLocals;
	}

	/**
	 * Returns the LabelNode corresponding to the given Label. Creates a new 
	 * LabelNode if necessary. The default implementation of this method uses
	 * the {@link Label#info} field to store associations between labels and
	 * label nodes.
	 * 
	 * @param l a Label.
	 * @return the LabelNode corresponding to l.
	 */
	protected LabelNode getLabelNode(final Label l) {
		if (!(l.info instanceof LabelNode)) {
			l.info = new LabelNode(l);
		}
		return (LabelNode) l.info;
	}

	private LabelNode[] getLabelNodes(final Label[] l) {
		LabelNode[] nodes = new LabelNode[l.length];
		for (int i = 0; i < l.length; ++i) {
			nodes[i] = getLabelNode(l[i]);
		}
		return nodes;
	}

	private Object[] getLabelNodes(final Object[] objs) {
		Object[] nodes = new Object[objs.length];
		for (int i = 0; i < objs.length; ++i) {
			Object o = objs[i];
			if (o instanceof Label) {
				o = getLabelNode((Label) o);
			}
			nodes[i] = o;
		}
		return nodes;
	}

	// ------------------------------------------------------------------------
	// Accept method
	// ------------------------------------------------------------------------
	/**
	 * Makes the given class visitor visit this method.
	 * 
	 * @param cv a class visitor.
	 */
	public void accept(final ClassVisitor cv) {
		String[] exceptions = new String[this.exceptions.size()];
		this.exceptions.toArray(exceptions);
		MethodVisitor mv = cv.visitMethod(access,
				name,
				desc,
				signature,
				exceptions);
		if (mv != null) {
			accept(mv);
		}
	}

	/**
	 * Makes the given method visitor visit this method.
	 * 
	 * @param mv a method visitor.
	 */
	public void accept(final MethodVisitor mv) {
		// visits the method attributes
		int i, j, n;
		if (annotationDefault != null) {
			AnnotationVisitor av = mv.visitAnnotationDefault();
			AnnotationNode.accept(av, null, annotationDefault);
			if (av != null) {
				av.visitEnd();
			}
		}
		n = visibleAnnotations == null ? 0 : visibleAnnotations.size();
		for (i = 0; i < n; ++i) {
			AnnotationNode an = (AnnotationNode) visibleAnnotations.get(i);
			an.accept(mv.visitAnnotation(an.desc, true));
		}
		n = invisibleAnnotations == null ? 0 : invisibleAnnotations.size();
		for (i = 0; i < n; ++i) {
			AnnotationNode an = (AnnotationNode) invisibleAnnotations.get(i);
			an.accept(mv.visitAnnotation(an.desc, false));
		}
		n = visibleParameterAnnotations == null
				? 0
				: visibleParameterAnnotations.length;
		for (i = 0; i < n; ++i) {
			List<?> l = visibleParameterAnnotations[i];
			if (l == null) {
				continue;
			}
			for (j = 0; j < l.size(); ++j) {
				AnnotationNode an = (AnnotationNode) l.get(j);
				an.accept(mv.visitParameterAnnotation(i, an.desc, true));
			}
		}
		n = invisibleParameterAnnotations == null
				? 0
				: invisibleParameterAnnotations.length;
		for (i = 0; i < n; ++i) {
			List<?> l = invisibleParameterAnnotations[i];
			if (l == null) {
				continue;
			}
			for (j = 0; j < l.size(); ++j) {
				AnnotationNode an = (AnnotationNode) l.get(j);
				an.accept(mv.visitParameterAnnotation(i, an.desc, false));
			}
		}
		n = attrs == null ? 0 : attrs.size();
		for (i = 0; i < n; ++i) {
			mv.visitAttribute((Attribute) attrs.get(i));
		}
		// visits the method's code
		if (instructions.size() > 0) {
			mv.visitCode();
			// visits try catch blocks
			n = tryCatchBlocks == null ? 0 : tryCatchBlocks.size();
			for (i = 0; i < n; ++i) {
				((TryCatchBlockNode) tryCatchBlocks.get(i)).accept(mv);
			}
			// visits instructions
			instructions.accept(mv);
			// visits local variables
			n = localVariables == null ? 0 : localVariables.size();
			for (i = 0; i < n; ++i) {
				((LocalVariableNode) localVariables.get(i)).accept(mv);
			}
			// visits maxs
			mv.visitMaxs(maxStack, maxLocals);
		}
		mv.visitEnd();
	}
}
